Mill valve system

ABSTRACT

A bypass valve and method of utilizing a bypass valve located inside of a tubular or mill that allows one set of equipment to operate, operating a second tool on demand, and then providing a fluid pathway for at least a third device to operate. The bypass valve has a through bore with the restriction. Fluid flows through the restriction at a first rate that is sufficient to operate a measuring while drilling tool. The fluid flow is then increased to a second rate where the restriction causes an increase in pressure within the bypass valve. The increase in pressure allows a packer typically below the bypass valve to be set. Fluid flow is then increased to a third rate causing a further increase in pressure within the bypass valve due to the restriction. The third pressure level allows an interior sleeve in the bypass valve to shift thereby isolating the downhole tool such as a packer while providing a new fluid flow path that partially bypasses the restriction allowing an even greater flow rate through the bypass valve.

BACKGROUND

Multilateral well drilling and production, where a wellbore may have multiple wells branching off of a common wellbore have become increasingly important as a way to both maximize drilling efficiency and to minimize the wellsite footprint on the surface.

In the past, a main wellbore was drilled. Once completed a packer was set in the well at a location in the well corresponding to the location that the window for the first branch or sidetrack well was desired. Once the packer was set the tool string was removed from the well and a measuring device was run into the well to determine the orientation of the keyslot or orientation device on top of the packer. After determining the orientation of the keyslot the measuring device was removed from the well and the whipstock/mill assembly was run into the well. A key on the bottom of the whipstock/mill assembly was preset on the surface, based upon the data gathered by the measuring device, so that the whipstock/mill assembly would be pointing in the desired direction when the whipstock/mill assembly was landed on the packer. The whipstock/mill assembly may then be used to cut a window into the casing so that a second well or branch may be drilled from the window and produced through the common wellbore.

In order to improve the efficiency of the drilling process, operators have streamlined the sidetracking operation by running the packer, the measuring device, and the whipstock/mill assembly into the well in a single operation. The typical packer used in single trip sidetrack operations is a hydraulically actuated packer.

Typically, the single trip whipstock/mill assembly has the packer or anchor attached beneath the whipstock/mill assembly and the measuring device, usually a measuring while drilling or MWD tool, is attached above the whipstock mill assembly. The MWD tool uses pressure pulses to send a signal to the surface that notifies the operator of the orientation and direction of the MWD tool and thus the orientation of the whipstock/mill assembly. To send the signal the MWD tool requires power to sense its direction and orientation as well as to send the signal to the surface. The power is provided by the drilling fluid. A typical MWD tool requires a flow rate from between 200 gallons per minute or GPM to about 1500 GPM.

One of the difficulties in utilizing a hydraulically actuated packer in the same assembly as an MWD tool is the requirement to provide sufficient hydraulic power to the MWD tool without prematurely setting the packer.

The present invention fulfills these needs and provides further related advantages.

SUMMARY OF THE INVENTION

The present invention is an improved bypass valve that allows the packer to be set at the proper depth while allowing the operator to use the MWD tool to properly orient the whipstock/mill assembly. The present invention also allows the operator to redirect the fluid flow, after setting the packer, so that full flow can pass through the mill during the cutting operation to remove the cuttings.

In an embodiment of the invention, the bypass valve is situated in the internal bore of the mill. The outer housing of the valve is attached directly to the internal bore of the mill, although the valve may be placed anywhere in the fluid flow above the packer. The valve also has an inner sleeve. The housing typically has at least three sets of ports.

A first port is located in the lower end of the valve housing and is essentially concentric with the housing. The first set of ports is typically a single port but any number of ports could be utilized. The first port may be a nozzle that allows flow though the valve so that the operator may flow a sufficient amount of fluid through the MWD tool to power the MWD tool allowing it to send a signal to the surface so that the assembly may be appropriately oriented. The first port is calibrated to allow a preset amount of fluid flow through the port at or below a certain pressure which typically allows the MWD tool to operate. By increasing the fluid flow through the port the pressure in the assembly may be increased in the valve so that the packer may be set upon demand.

A second set of ports are located towards the lower end of the valve housing. The second set of ports are large bore ports to bypass the restriction of the nozzle formed by the first port thereby allowing essentially full bore flow through the valve once the MWD tool is oriented and the packer/anchor is actuated hydraulically. A third set of ports is typically a single port and is connected via a capillary tube to allow the operator to set the packer when desired.

The sleeve is situated in the housing so that the second set of ports is obstructed by the sleeve while the third port is open. A shear device or lock retains the sleeve so that when fluid flows from the surface at a predetermined rate, the fluid flow will cause a pressure rise in the valve. At a calculated pressure the shear device is released allowing the sleeve to move. The shear device may be a shear screw, a c-ring, a pin, a cam, or any other type of device that releases upon a preset threshold of force.

When released the sleeve travels a preset distance which upon reaching the sleeve is engaged by a retention device. The retention device may be a retainer screw, a pin, a c-ring, a retention profiled mating component or any other type that results in a retainer mode.

In the second position, after the shear device has released the sleeve, the released sleeve blocks third port preventing or minimizing any further passage of fluid though the third port while opening second set of ports to allow essentially the sleeve's full bore fluid flow through the valve. In some embodiments of the present invention a latch device may hold the sleeve in the second position thereby reducing the sleeve's ability to return to the first position.

In previous bypass valves the port or other fluid connection, that is used to set the packer, is not closed allowing high pressure and sometimes erosive fluid to jet about the mill reducing the mill's efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a mill valve in its closed or run-in condition.

FIG. 2 is an orthogonal depiction of the mill valve in FIG. 1.

FIG. 3 is a depiction of the mill valve in its open.

FIG. 4 is an orthogonal depiction of the mill valve in FIG. 3.

FIG. 5 is an alternative embodiment of an open mill valve where the interior sleeve is prevented from any further movement towards the bottom of the well by end cap.

FIG. 6 is an alternative embodiment of an open mill valve where the interior sleeve is prevented from any further movement towards the bottom of the well by a pin.

DETAILED DESCRIPTION

FIG. 1 depicts a mill bypass valve of the present invention in its closed or run-in condition. The mill body 100 has an upper end one or two and a lower end 104 attached to the exterior of the mill body in a channel 106 is a capillary tube 110. The capillary tube 110 is in turn connected to a fitting 112 that is in turn attached, typically by threads but welding, adhesives, or any other means known could be used, to a port 114 in the mill body 110.

The mill valve 120 has a housing 122 that may be attached to the interior surface 116 of the mill body 100. The housing 122 may be attached to the interior surface 116 of the mill body 100 by threads, press fit, welding, snap rings, or any other means known in the industry. In the embodiment shown in FIG. 1 the housing 122 is retained against further downward movement towards the lower end 104 of the mill body 100 by mill body shoulder 124 which interacts with mill valve shoulder 12. Additionally, the housing 122 is retained against upward movement towards the upper end 102 of the mill body 100 by at least one retaining screw 128. While the retaining screw 128 is shown, any type of retaining means such as snap ring or retention means may be used. The retaining screw 128 is typically threaded into a channel 130 that is cut in the mill body 100. The channel 130 in the mill body 100 is in turn aligned with the channel 132 in the housing 122 of the mill valve 120. The channel 130 has a first larger diameter 134 towards the exterior of the housing 122 and a second smaller diameter 136 towards the interior of the housing 122.

The mill valve 120 also has an interior sleeve 140. The interior sleeve 140 is concentric with the housing 122. Additionally the interior sleeve's 140 outer surface 142 abuts the housing's 122 inner surface 144. The interior sleeve 140 also has a channel 146. The channel 146 is the same diameter as the second smaller diameter 136 and is aligned with channel 132 and typically has a shear means such as a shear screw or shear pin 147 is inserted partly into channel 146 and partly into channel 130.

Towards the lower end 104 of the interior sleeve 140 is a port 150. The port 150 is configured such that its smallest diameter 154 is smaller than the inner diameter 152 of the interior sleeve 140.

At least a portion of the interior sleeve 140 typically towards the lower end 104 has a diameter 156 that extends past the interior surface 144 of the housing 122. Interior sleeve 140 also has a recessed channel 160 that allows pin 162 to extend radially inward beyond the housing's 122 inner surface 144. Ports 174 are formed through interior sleeve 140 allow access from the interior of interior sleeve 140 to the exterior of interior sleeve 140. Typically multiple ports 174 are spaced circumferentially around the interior sleeve 140

The interior sleeve 140 additionally has a series of packer ports 180 that are formed through the interior sleeve 140 to allow access from the interior of interior sleeve 140 to the exterior of interior sleeve 140. Packer ports 180 may be isolated from ports 174 by use of a seal such as O-ring 181. Interior sleeve 122 also has a set of ports 186 that when the mill valve 120 is in the closed or run-in position the ports 186 are aligned with packer ports 180 to allow access from the interior of interior sleeve 140, through packer ports 180, through ports 186, through to fitting 112, and to capillary tube 110.

The mill valve 120 as depicted in FIG. 1 is in its closed or run-in condition. In the closed condition a fluid is pumped through the interior of the mill valve as depicted by arrows 182. The fluid as it is pumped through the interior sleeve 140 of the mill valve 120 the fluid exits the interior sleeve 140 through port 150. The flow area of port 150 is calculated so that a sufficient amount of fluid is able to pass through port 150 at a first predetermined pressure such that the amount of fluid passing through port 150 is sufficient to operate the measuring while drilling tool upstream of the mill valve 120. The fluid moving through the interior sleeve 140 is in fluid communication with capillary tube 110 through ports 180 in the interior sleeve 140, through ports 186 in the housing 122, through fitting 112, and finally connecting to capillary tube 110 allowing any pressure exerted by the fluid on the interior of interior sleeve 140 to be transmitted via the capillary tubing to the packer (not shown) downstream of the mill valve 120. As long as fluid flow through interior sleeve 140 remains below the first predetermined level the pressure exerted on the downstream packer is insufficient to actuate the downstream packer.

As fluid flow through interior sleeve 140 is increased above the first predetermined level to a second predetermined level thereby increasing the pressure upon the downstream packer via the capillary tube 110. The pressure increase above the first predetermined level is due to the fixed area of port 150. Port 150 has a maximum amount of fluid that may pass through it at any given pressure level. In order to force additional fluid flow through the port 150 the pressure of the fluid must increase. In this case, upon demand, the pressure is increased to a second predetermined pressure level in order to actuate the downstream packer. While the second predetermined pressure level is sufficient to actuate the downstream packer, the pressure acting upon the surfaces of the interior sleeve 140 are insufficient to overcome the shear means such as shear pin 147. Therefore the interior sleeve 140 is retained in place at the second predetermined pressure level.

FIG. 2 is an orthogonal depiction of the mill valve 120 in FIG. 1 without showing the mill body 100. The reference numerals and descriptions from FIG. 1 are applicable to the mill valve body 120 shown in FIG. 2.

FIG. 3 is a depiction of the mill valve 120 after the fluid flow through port 150 has been increased such that the third predetermined pressure level is reached. Once the pressure level is increased to the third predetermined level, the force exerted upon the interior sleeve 140 causes the interior sleeve 140 to shear the shear pin 147 and further forcing the interior sleeve 140 to move to the right or towards the lower end 104 of the mill body 100. With the interior sleeve 140 shifted to the right ports 186 and 180 no longer line up thereby isolating capillary tube 110 and the packer below the mill assembly. Additionally with the interior sleeve 140 shifted to the right fluid access through port 174 in the interior sleeve 140 is facilitated. By allowing the fluid to flow around the lower end of the exterior of interior sleeve 140 as indicated by arrows 200 the restricted area of port 150 is no longer able to restrict fluid flow through the interior sleeve 140 therefore the fluid flow may be increased without an additional rise in pressure through the mill valve 120. The increased fluid flow is useful to allow the fluid to flow through the mill when the mill is in operation and to remove the particles produced as the mill cuts. Finally with the interior sleeve 140 shifted to the right the shoulder 172 on the exterior surface of interior sleeve 140 contacts pin 162 and is thereby prevented from moving any further towards the lower end 104 of mill body 100. Pin 162 may be a screw, a pin, or formed as a part of the housing 122.

FIG. 4 is an orthogonal depiction of the mill valve 120 in FIG. 3 without showing the mill body 100. The reference numerals and descriptions from FIG. 1 are applicable to the mill valve body 120 shown in FIG. 4.

FIG. 5 is an alternative embodiment of the open mill valve depicted in FIG. 3. In FIG. 5 the interior sleeve 240 is prevented from any further movement towards the bottom of the well by end cap 262. End cap 262 has a shoulder 263 that with interior sleeve shifted towards the bottom of the well contacts shoulder 265 of the housing 222 to prevent any further movement towards the bottom of the well by interior sleeve 140. End cap 262 is coupled to the interior sleeve 245 threads 267. While in this instance threads 267 are shown to couple end cap 262 to interior sleeve 240 pins, welding, or any other means known may be used a couple interior sleeve 242 end cap 262. Additionally the end cap 262 may be formed as an integral part of interior sleeve 242.

FIG. 6 is an alternative embodiment of the open mill valve depicted in FIG. 3. In FIG. 6 the interior sleeve 340 is prevented from any further movement towards the bottom of the well by pin 362. Housing 322 has at least one slot 363 milled through it. Pin 362 is attached to the interior sleeve 340, by screwing it into place, pressing it into place, welding it into place, formed as a part of, or any other means known in the industry, such that a portion of pin 362 extends into slot 363. As interior sleeve 340 is forced towards the lower end of the well pen 362 moves within slot 363 until a portion of pin 362 rests again shoulder 367 thereby stopping further movement of interior sleeve 340 towards the bottom of the well.

While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. For example, the implementations and techniques used herein may be applied to any bypass valve in a tubular.

Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter. 

What is claimed is:
 1. A method for providing alternate fluid pathways comprising: locking a sleeve in an interior of a housing in a first position with a lock; moving the sleeve from the first position to a second position; restricting fluid flow through interior of the housing; allowing fluid flow through a third port; pressurizing the housing to overcome the lock; and moving the sleeve from the first position to the second position.
 2. The method of claim 1 wherein, fluid flow through the third port is blocked and fluid flow through the second port is allowed once the sleeve moves from the first position to the second position.
 3. The method of claim 1 wherein, fluid flow through the second port is less restrictive than fluid flow through the interior of the housing.
 4. The method of claim 1 wherein, the housing has a lock between the housing and the sleeve; wherein the lock retains the sleeve in the first position.
 5. The method of claim 4 wherein, the sleeve located in the interior of the housing has a second position.
 6. The method of claim 1 wherein, the sleeve is retained after moving a predetermined distance.
 7. The method of claim 1 wherein, a pressure drop in the fluid flow signals the lock release.
 8. A hydraulic bypass valve comprising: a housing having a through bore, an interior sleeve within the housing through bore, wherein the interior sleeve has an interior fluid flow path, a fluid flow restriction in the interior fluid flow path, the interior sleeve having a first position within the housing wherein a first port in the housing is aligned with a second port in the interior sleeve, the interior sleeve having a second position within the housing wherein a second fluid flow path enhances the interior fluid flow path.
 9. The hydraulic bypass valve of claim 8 wherein, the interior sleeve is held in the first position by a shear pin.
 10. The hydraulic bypass valve of claim 8 wherein, the interior sleeve is retained in the second position by a protrusion from the housing that interacts with the interior sleeve.
 11. The hydraulic bypass valve of claim 8 wherein, the interior sleeve is retained in the second position by a protrusion from the interior sleeve that interacts with the housing.
 12. The hydraulic bypass valve of claim 8 wherein, the interior sleeve is retained in the second position by an endcap that interacts with the housing.
 13. The hydraulic bypass valve of claim 8 wherein, the first port and the second port when aligned allow fluid access from the interior fluid flow path to an exterior of the housing.
 14. A method of operating a downhole mill assembly comprising: pumping a fluid at a first rate through a sleeve having an interior bore and a first port, wherein the interior bore has a flow restriction, pumping the fluid at a second rate through the sleeve to cause a pressure to reach a first predetermined level wherein the pressure increase to the first predetermined level actuates a tool through the first port, pumping the fluid at a third rate through the sleeve to cause the pressure to reach a second predetermined level, wherein the pressure increase to the second predetermined level moves the sleeve within a housing to access a second port.
 15. The method of operating a downhole mill assembly of claim 14 wherein, accessing the second port enhances a total fluid flow through the sleeve.
 16. The method of operating a downhole mill assembly of claim 14 wherein, moving the sleeve within the housing isolates the tool.
 17. The method of operating a downhole mill assembly of claim 14 wherein, the interior sleeve is held in a first position by a shear pin.
 18. The method of operating a downhole mill assembly of claim 14 wherein, the interior sleeve is retained in a second position by a protrusion from the housing that interacts with the interior sleeve.
 19. The method of operating a downhole mill assembly of claim 14 wherein, the interior sleeve is retained in the second position by a protrusion from the interior sleeve that interacts with the housing.
 20. The method of operating a downhole mill assembly of claim 14 wherein, the interior sleeve is retained in the second position by an endcap that interacts with the housing. 